Analog storage devices are sometimes used for delaying and/or for changing the time scale of analog waveforms. For example, a storage device used to "time stretch" an analog waveform is disclosed in U.S. Pat. No. 4,152,606, "Waveform Capture Device" issued May 1, 1979, and assigned to the present assignee. The delayed and/or time transformed output signal of these devices often differs from the desired "true" output signal by a significant d.c. offset, a significant change in voltage scale (i.e., a non-unity gain) and by distortion. All of these errors are typically dependent on temperature, power supply voltage, and life.
In some devices (such as the above-mentioned "Waveform Capture Device") operation is based on sampling of the input signal, each sample being stored in a different part ("bin") of the device. In this case, the offset, gain, and distortion errors can be different from bin to bin, thus superimposing a systematic noise on the desired output signal.